GLU Java port used in JOGL supports nurbs but it is not supported by JMonkeyEngine 2. I have not checked with JMonkeyEngine 3. Some things cannot be simplified without being driven less powerful. Anyway, understanding OpenGL is helpful to use higher level APIs and especially 3D engines, you're more autonomous with them when you're able to fix any bug in their implementations and you can use them with a bigger ease when you understand the underlying concepts on which they are based. The lazy approach consisting in learning the strict minimum to do the maximum leads to nowhere.

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